1. Field of the Invention
Aspects of the present invention relate to a thin film deposition apparatus, and more particularly, to an apparatus for forming a fine pattern on a large substrate.
2. Description of the Related Art
Organic light-emitting display devices have a larger viewing angle, better contrast characteristics, and a faster response rate than other display devices, and thus have drawn attention as a next-generation display device.
In general, organic light-emitting display devices may generate visible light by using light emission when holes and electrons injected from anode and cathode electrodes are recombined in an organic emission layer. However, it is difficult to achieve high light-emission efficiency with such a structure, and thus organic layers, such as an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer, are optionally additionally interposed between the emission layer and each of the electrodes.
Electrodes, an organic emission layer, and an organic layer of such an organic light-emitting display device may be formed using a variety of methods one of which is a deposition method. When an organic light-emitting display device is manufactured by using the deposition method, a fine metal mask (FMM) having the same pattern as a thin film to be formed is disposed to closely contact a substrate, and a thin film material is deposited over the FMM in order to form the thin film having the desired pattern.
However, it is actually difficult to form a fine pattern of an organic thin film, such as an organic emission layer or an organic layer, and the luminous efficiency of red, green, and blue colors may vary according to the pattern and thickness of the organic thin film. Thus, there is a limit in improving the luminous characteristics of organic light-emitting display devices.
Also, recently, there is higher demand for large-sized display devices but it is difficult to pattern organic thin films on a large surface using conventional thin film deposition apparatuses. Thus it is difficult to manufacture large-sized organic light-emitting display devices having satisfactory levels of driving voltage, current density, luminance, color purity, luminous efficiency, lifetime, etc.